PAT A1114 family property (25)

//用到并查集，有关系的人在一个圈子里，合并的时候注意根设为id较小的那个。遍历统计root和计房产数和面积，我单独开了一个数组放rootid

#include<cstdio>
#include<vector>
#include<set>
#include<algorithm>
using namespace std;
int n;
int father[10010];
int isroot[10010];
int familynum[10010]={0};
double avgsets[10010]={0};
double avgarea[10010]={0};
set<int> idset;
vector<int> rootid;
struct node{
int id;
int father,mother;
int k;
vector<int> child;
int mestate;
int area;
}node[10010];
void init(){
for(int i=0;i<10010;i++){
father[i]=i;
}
}
int findfather(int x){
int a=x;
while(x!=father[x]){
x=father[x];
}
while(a!=father[a]){
int z=a;
father[a]=x;
a=father[z];
}
return x;
}
void Union(int a,int b){
int faA=findfather(a);
int faB=findfather(b);
if(faA!=faB){
if(faA<faB) father[faB]=faA;
else father[faA]=faB;
}
}
int cmp(int a,int b){
if(((double)avgarea[a]/familynum[a])!=((double)avgarea[b]/familynum[b])) return ((double)avgarea[a]/familynum[a])>((double)avgarea[b]/familynum[b]);
else return a<b;
}
int main(){
init();
scanf("%d",&n);
int id,mo,fa,k,temp,estate,area;
int i;
for(i=0;i<n;i++){
scanf("%d%d%d%d",&id,&fa,&mo,&k);
node[id].father=fa;
idset.insert(id);
if(fa!=-1){
Union(id,fa);
idset.insert(fa);
}
node[id].mother=mo;
if(mo!=-1){
Union(id,mo);
idset.insert(mo);
}
node[id].k=k;
for(int j=0;j<k;j++){
scanf("%d",&temp);
node[id].child.push_back(temp);
Union(id,temp);
idset.insert(temp);
}
scanf("%d%d",&estate,&area);
node[id].mestate=estate;
node[id].area=area;
}
set<int>::iterator it=idset.begin();
int num=0;
for(it;it!=idset.end();it++){
if(*it==findfather(*it)){
isroot[*it]=1;
rootid.push_back(*it);
num++;
}
familynum[findfather(*it)]++;
avgsets[findfather(*it)]+=node[*it].mestate;
avgarea[findfather(*it)]+=node[*it].area;
}
printf("%d\n",num);
sort(rootid.begin(),rootid.end(),cmp);
vector<int>::iterator it2=rootid.begin();
for(it2=rootid.begin();it2!=rootid.end();it2++){
if(isroot[*it2]==1){
printf("%04d %d %.3f %.3f\n",*it2,familynum[*it2],(double)avgsets[*it2]/familynum[*it2],(double)avgarea[*it2]/familynum[*it2]);
}
}
system("pause");
return 0;
}